Exploring the Effect of the Number of Characteristic Groups in Melaminebased Polymers on the Photocatalytic Performance

: Three polymers containing different numbers of thiophene groups were constructed. Degradation experiments on the aqueous solutions of tetracycline and norfloxacin revealed that the polymer with three thiophene groups in the monomer indicated the best degradation efficiency of 73.7% for tetracycline and 56.9% for norfloxacin. Moreover, this polymer had a relatively stronger ability to separate and transport photocharging carriers under visible light. Therefore, the photocatalytic performance of conjugated polymers could be regulated by changing the number of characteristic groups. Background: Antibiotic residues in the environment are considered as one of the most serious sources of environmental pollution. Although catalyst photodegradation is regarded as the most promising strategy to solve environmental pollution-related problems, it still requires new and advanced photocatalysts. Objective: To design new organic conjugated material structures. Material and Methods: Three polymers (ThME-1, ThME-2, and ThME-3) were prepared by the condensation of melamine with 2, 5-thiophenedicarboxaldehyde, thieno[3, 2-b]thiophene-2, 5-dicarbaldehyde, and dithieno[3, 2-b:2’, 3’-d]thiophene-2, 6-dicarbaldehyde. The photocatalytic performance of these polymers was investigated by testing their diffused light absorption capacity, photocurrent response, AC impedance, specific surface area, fluorescence, and thermal stability. Results: ThME-3, containing three thiophene groups in the monomer, manifested the best degradation efficiency of 73.7% for tetracycline and 56.9% for norfloxacin. Conclusion: The photocatalytic performance of conjugated polymers could be regulated by changing the number of characteristic groups.

Download Full-text

ZnCDs/ZnO@ZIF-8 Zeolite Composites for the Photocatalytic Degradation of Tetracycline

Catalysts ◽

10.3390/catal11080934 ◽

2021 ◽

Vol 11 (8) ◽

pp. 934

Author(s):

Yong Cheng ◽

Xiuxiu Wang ◽

Yu Mei ◽

Dan Wang ◽

Changchun Ji

Keyword(s):

Catalytic Activity ◽

Photocatalytic Degradation ◽

Photocatalytic Performance ◽

Active Species ◽

Degradation Efficiency ◽

Experimental Result ◽

Porous Nanostructure ◽

Resultant Material

Considering the photocatalytic performance of CDs, ZnO, and the unique porous nanostructure and stability of ZIF-8, we prepared ZnCDs/ZnO@ZIF-8 zeolite composites. The resultant material represented an enhanced ability for the photodegradation of TC compared with that of ZnCDs and ZnO. The photocatalytic degradation efficiency reached over 85%. The catalytic activity of the composites was maintained after four cycles. The experimental result indicated that ×O2 radical was the active species in the reaction.

Download Full-text

A Characterization Study of Morphology and Properties of Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH)/Aloe Vera Fibers Biocomposites: Effect of Fiber Surface Treatments

Proceedings ◽

10.3390/cgpm2020-07183 ◽

2020 ◽

Vol 69 (1) ◽

pp. 38

Author(s):

Celia Idres ◽

Mustapha Kaci ◽

Nadjet Dehouche ◽

Idris Zembouai ◽

Stéphane Bruzaud

Keyword(s):

Thermal Stability ◽

Surface Morphology ◽

Water Absorption ◽

Loss Modulus ◽

Aloe Vera ◽

Fiber Surface ◽

Complex Viscosity ◽

Absorption Capacity ◽

Characterization Study ◽

Efficient Route

This paper aims to investigate the effect of different chemical modifications of biocomposites based on poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH) and aloe vera bio-fibers incorporated at 20 wt%. The fiber surface was modified with alkaline, organosilanes, and combined alkaline/organosilanes. Surface morphology, thermal stability, water absorption capacity, and rheological behavior of the modified biocomposite materials were studied, and the results compared to both unmodified biocomposites and neat PHBH. The study showed that the modified biocomposites with both alkaline and organosilanes exhibited an improved surface morphology, resulting in a good fiber/matrix interfacial adhesion. As a result, increases in complex viscosity, storage modulus, and loss modulus were observed, whereas water absorption was reduced. Thermal stability remained almost unchanged, with the exception of the biocomposite treated with alkaline, where this property decreased significantly. Finally, the coupling of alkaline and organosilane modification is an efficient route to enhance the properties of PHBH biocomposites.

Download Full-text

High performance self-heated membrane distillation system for energy efficient desalination process

Journal of Materials Chemistry A ◽

10.1039/d0ta11724b ◽

2021 ◽

Author(s):

Wei-Song Hung ◽

Subrahmanya T M ◽

Po Ting Lin ◽

Yu-Hsuan Chiao ◽

Januar Widakdo ◽

...

Keyword(s):

Environmental Pollution ◽

Energy Efficient ◽

High Performance ◽

Membrane Distillation ◽

Energy Crisis ◽

Safe Water ◽

Global Challenges ◽

Promising Strategy ◽

Distillation System

Membrane distillation (MD) based desalination process is thought to be a promising strategy to address global challenges such as safe water-energy crisis and environmental pollution. Here, we demonstrate a novel...

Download Full-text

(002) facets exposed and controllable thickness of CdS nanobelts drive desirable hydrogen-adsorption free energy (△GH) for boosting visible-light photocatalytic performance

Catalysis Science & Technology ◽

10.1039/d1cy01385h ◽

2021 ◽

Author(s):

Dejian Yan ◽

Zhiyong Xue ◽

Feng Chen ◽

Xia Liu ◽

Zhenhua Yang ◽

...

Keyword(s):

Free Energy ◽

Visible Light ◽

Environmental Pollution ◽

Economically Disadvantaged ◽

Photocatalytic Performance ◽

Hydrogen Adsorption ◽

Co Catalysts ◽

Adsorption Free Energy ◽

Cds Nanobelts ◽

Visible Light Photocatalytic

In order to obtain the high photocatalytic performance, co-catalysts loading is the most commonly used, which is economically disadvantaged and environmental pollution. Here, we combine the strategy of controllable thickness...

Download Full-text

Simple Fabrication of PVA–ZnS Composite Films with Superior Photocatalytic Performance: Enhanced Luminescence Property, Morphology, and Thermal Stability

ACS Omega ◽

10.1021/acsomega.8b02807 ◽

2019 ◽

Vol 4 (4) ◽

pp. 6144-6153 ◽

Cited By ~ 6

Author(s):

Mohammad Mizanur Rahman Khan ◽

Subrata Pal ◽

Md. Mainul Hoque ◽

Md. Rashedul Alam ◽

Muhammad Younus ◽

...

Keyword(s):

Thermal Stability ◽

Luminescence Property ◽

Photocatalytic Performance ◽

Composite Films ◽

Enhanced Luminescence

Download Full-text

Effective Cocatalyst Pt/PtO Nanodots on La2O3 Microspheres for Degradation of Methyl Orange

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2020.17392 ◽

2020 ◽

Vol 20 (5) ◽

pp. 3140-3147 ◽

Cited By ~ 5

Author(s):

Zehao Zhao ◽

Jiaolong Liu ◽

Ming Qin ◽

Kaichang Kou ◽

Guanglei Wu ◽

...

Keyword(s):

Methyl Orange ◽

Organic Pollutants ◽

Rate Constant ◽

Shell Structure ◽

Photocatalytic Performance ◽

Xps Analysis ◽

Sem Images ◽

Promising Strategy ◽

Xrd Patterns ◽

Degradation Of Methyl Orange

Platinum (Pt) has been intensively studied as an effective cocatalyst for photocatalysis, but most reports have focused on metallic Pt rather than PtO. Here, Pt/PtO nanodots were deposited on porous yolk–shell La2O3 microspheres. XRD patterns and XPS analysis demonstrated the coexistence of Pt and PtO, which was beneficial for photocatalytic performance. SEM images showed the yolk–shell structure of La2O3, and TEM images demonstrated that the Pt/PtO nanodots were uniformly distributed on the La2O3 microspheres. The rate constant of the hybrid was calculated to be 0.00656 min−1 for methyl orange (MO) degradation, while that of bare La2O3 was only 0.00303 min−1. This work suggests that the use of the deposited cocatalyst Pt/PtO on La2O3 microspheres is a promising strategy for the degradation of organic pollutants.

Download Full-text

Case Study about the Energy Absorption Capacity of Metal Oxide Varistors with Thermal Coupling

Energies ◽

10.3390/en12030536 ◽

2019 ◽

Vol 12 (3) ◽

pp. 536 ◽

Cited By ~ 1

Author(s):

Flaviu Frigura-Iliasa ◽

Sorin Musuroi ◽

Ciprian Sorandaru ◽

Doru Vatau

Keyword(s):

Thermal Stability ◽

Metal Oxide ◽

Thermal Activation ◽

Absorption Capacity ◽

Technical Solution ◽

Thermal Coupling ◽

Thermal Exchange ◽

Surge Arresters ◽

Thermal Stability Of

Metal oxide varistors are applied today inside modern surge arresters for overvoltage protection for all voltage levels. Their main issue is the thermal activation of their crossing current, which could lead to complete destruction by thermal runaway. This article presents a new technological solution developed in order to increase the thermal stability of metal oxide varistors. It consists in connecting in parallel two or more similar varistors (for dividing their current), having a thermal coupling between them (for equalizing their temperatures and forcing them to act together and simultaneously as much as possible). Starting from a finite element computer model performed for each situation (varistor standalone or parallel), up to real measurements, the thermal stability of the equipment was analyzed in permanent and impulse regime. Experiments were carried out in the same conditions. Experimental data obtain from two disk varistors corresponds very well to simulations, proving that parallel connection of varistors, combined with a thermal exchange between them is an efficient technical solution for thermal stability improvement, even if not apparently economically justified.

Download Full-text

Controlled synthesis and photocatalytic performance of biocompatible uniform carbon quantum dots with microwave absorption capacity

Applied Surface Science ◽

10.1016/j.apsusc.2020.145751 ◽

2020 ◽

Vol 512 ◽

pp. 145751 ◽

Cited By ~ 2

Author(s):

Hanqi Zhang ◽

Hong Wang ◽

Ying Wang ◽

Baifu Xin

Keyword(s):

Quantum Dots ◽

Microwave Absorption ◽

Photocatalytic Performance ◽

Carbon Quantum Dots ◽

Absorption Capacity ◽

Controlled Synthesis

Download Full-text

Preparation and Properties of CaCO3-Supported Nano-TiO2 Composite with Improved Photocatalytic Performance

Materials ◽

10.3390/ma12203369 ◽

2019 ◽

Vol 12 (20) ◽

pp. 3369

Author(s):

Jie Wang ◽

Sijia Sun ◽

Lei Pan ◽

Zhuoqun Xu ◽

Hao Ding ◽

...

Keyword(s):

Photocatalytic Degradation ◽

Photocatalytic Performance ◽

Uv Light ◽

Interaction Mechanism ◽

Pure Tio2 ◽

Degradation Efficiency ◽

Nano Tio2 ◽

Composite Photocatalyst ◽

Tio2 Particles ◽

Grinding Machine

In order to improve the photocatalytic degradation efficiency of nano-TiO2, reduce its usage and realize recycling and reuse, CaCO3–TiO2 composite photocatalyst was prepared with calcium carbonate (CaCO3) and TiO2 in a grinding machine through the integration of grinding depolymerization, dispersion and particle composition. The photocatalytic degradation performance, recycling performance, structure and morphology of CaCO3–TiO2 were studied. The interaction mechanism between CaCO3 and TiO2 and the improvement mechanism for the photocatalytic performance of TiO2 were also discussed. The results show that under the UV light irradiation for 20 and 40 min, the degradation efficiency of methyl orange by the composite photocatalyst with 40% TiO2 (mass fraction) was 90% and 100%, respectively. This was similar to that of pure TiO2, and the performance of the composite photocatalyst was almost unchanged after five cycles. CaCO3–TiO2 is formed by the uniform loading of nano-TiO2 particles on the CaCO3 surface, and the nano-TiO2 particles are well dispersed. Due to the facts that the dispersion of nano-TiO2 is improved in the presence of CaCO3 and the charge transport capability is improved through the interfacial chemical bonds between CaCO3 and TiO2, the formation of this complex is an intrinsic mechanism to improve the photocatalytic efficiency of nano-TiO2 and reduce its usage in application processes.

Download Full-text